Be it the scale of a completely explorable island that suggests open-world RPG versus a tiny corridor shooter. Or that tantalising upgrade from blunt wooden plank to electrified baton, then blade-covered bat. Or your standard lumbering Undead being pushed aside by a hulking giant with a head like a battering ram and a kick that'd cave in your ribcage.

It's all about escalation, and Techland's Dead Island is keen to introduce something new into the zombie genre. And after an hour of hands-on that felt like ten minutes, it's clear this isn't zombified in the same mould as Left 4 Dead, and that there's plenty of substance past the skilful editing of that announcement trailer.

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Size matters. And it's Dead Island's sense of scale - something that can't be conveyed in screens nor even a ten-minute video - that is the immediate reason for feeling overawed.

The four-player demo we're playing today lacks the five minute on-screen countdown that limited the E3 build, that more concession to the long queues such a show creates than to hide Dead Island's secrets, of which the the game has many. A post-match map check has us gazing upon a huge computer board map of roads and backstreets that makes up this particular town, and a vast chunk of coloured section showing just how much we <i>didn't<i> get to explore.

It's a surprise after being used to Left 4 Dead's hefty directing of the action into compact streets. The several years playing Valve's series likely the reason why it takes so long before our group tentatively strays from main streets into back alleys, a tinge of disbelief that ladders and across rooftops are interactive rather than background placements, before capering into uninhibited charges over fences and through parking lots, uncaring about direction but also half-expecting an invisible wall that suddenly block our path. It never appears, though our guide frantically calls us back on the headset as he's beset by walls of chomping teeth and clutching hands, a solitary Twinkie to be torn and swallowed whole in the eyes of the undead horde.

The zombies in Dead Island are a bunch of Bertie Bassett's, taking in all sorts of zombie types that have grown from the cinema screen and mutated in the videogame world. We get the slow sluggish types, the faster paced runners, the stronger berserker thugs who soak up damage, and then the 'specials' - our words, not Techland's - who require teamwork to take down.

The hierarchy of any good zombie experience, as Dead Island is, limits numbers as you work up the system; we could make a macabre version of our Church safe-house using the bodies of the standard zombies strewn over the town come the end of our session, but barely a missionary's hut from the specials' remains. As it is, you're never more than a couple of blocks away from an encounter with one of the big fellas, who block the game's fast-paced flow like a violent discharge into the toilet, requiring all hands and devices within reaching distance to clear the way.

Rams are the main concern; straightjacketed to keep their arms restrained (and, as one representative suggests, a hint towards the outbreak having more sinister undertones than first thought) these seven-foot freaks put enough pounding in the kicks they lash out - enough to knock you down stunned, or even fatally wound you - to earn your respect. Their bizarre body proportions lead to a tiny leg shuffle that'd have you laughing in derision, if the vast upper body mass wasn't steamrolling in your direction at some fair clip. Directions? Stand near a car wreck, dodge last second to knock them senseless, and have no guilt for getting the boot in from behind.

There's Suiciders too, swollen bags off meat and blood that'll shamble towards you and explode - easily handled with a gunshot, but even having a weapon that uses bullets is a rarity on the holiday isle, with the odd weapon cases dotted around the island like treasure chests more likely to yield a stick or shovel at best in their cruel Russian Roulette of Randomness. You're best picking up whatever's strewn on the roadside, rescuing survivors in supply-heavy stores or locating an upgrade bench somewhere.

These three, along with main missions, aid in stringing together your general ramblings around the apocalypse-hit island. There's a nice RPG flair here that's the same setup as one of the best parts of Dead Rising; along with the main mission of the moment - ours a simple course of sticking up posters on community boards around town - you're free to add an optional side-quest if you stumble upon other survivors, racking up objectives like shopping prices on a supermarket till. A sub-menu keeps track of everything, and the mini-map tags your targets for easy directions.

This ever-growing customisable structure of Dead Island's gameplay is something of a main attraction, and nicely some side-quests are built for pairs rather than foursomes, letting you split and divide if you're playing with three friends. With the amount of debris and destruction wrought on the island, weapons aren't far away - though there's a massive difference between a cement block and a shotgun.

Continuing the RPG-vibe, all weapons have damage meters, becoming less deadly over time. You can repair and upgrade your weapons at benches located through the island; the only one we found was in the Church where we started our play-through - guess even God needs to do DIY on occasion. Upgrades cost money and parts - salvaging material helps push you to explore every area in your travels - but the result is worth it. Customised weapons disembowel enemies of their energy - hit points flash up over zombies to denote damage strength - while having secondary uses. A bayonet with a sticky bomb attached can be tossed into a zombie's flesh and used as a timed grenade; just communicate with friends before throwing, okay?

Being vocal is important in Dead Island. Focusing the combat mechanics in and around melee attacks has the obvious side-effect of necessitating agreed-on tactics during pitched battles with waves of zombies. Although there's nothing stopping every player weighing in on a scrap, the ability of said timed grenades, as well as grabbing handily placed gas canisters and exploding them means close proximities of friends have to be judged, which focuses the need of communication.

Button-bashing won't get you far. An on-screen stamina bar dictates your sprinting speed and your endurance for attacks; remember, this is your Average Joe on vacation gone wrong, not Carl Weathers circa 1985.

It's a good addition. There's a rhythm to melee combat here that riffs similarly to Monolith's Condemned, a need to pace your strikes between blocks, while a kick staggers your attacker backwards to give you some breathing room. There's a side-hop move to dodge charges, and zombies have their own striking patterns, so reading body language is essential. While med-kits are supplied to revive fallen comrades, their supply is limited - you'll die of bites before you overdose on meds.

Another plus in Dead Island's favour, and one that suggests the game's built for long play sessions rather than brief engagements is the character skill trees, which branch off into damage (both taken and dealing) as well as weapon accuracy, offering small increments to your chosen character's ability over time.

The four survivors are balanced out to provide the classic class-style setup, tank, all-rounder, fast-pace assassin and the like, and each gains buffs in utilising weapons connected to their class. Each character also can charge and pull off a 'rage'-type ability; while playing as Logan we kicking in a slow-mo technique that allowed us to rapidly fire off instant-kill knife throws on standard zombies for a short while. There's jump-in/jump-out options here - friends can stay for a mission or two, then leave, but while you're on your own, narrative cut-scenes will continue the illusion there's three survivors alongside you.

We've little chance to get to dig into the characters' personalities; its arguably superfluous in such a game anyway, but would give us a better indication as to the tone that Techland is aiming for here.

That first trailer delivered an emotional suckerpunch, and the contrast between the idyllic postcard-snap of the distant landscapes and the brutality of the rain-lashed streets (weather effect will be narrative-driven rather than dynamic) you fight for your life on suggests horror in the true brown trousers style.

Yet the zombies are never in such great number that you feel overwhelmed, and even the Ram becomes more low-level interference than threat once his moves are learnt. However, this is but one slice from the game, and despite the lifting of the five-minute clock, the demo is likely purposely manufactured to teach rather than terrorise first-time players.

The game's scope is impressive, its mechanics interesting, and there's a definite wish to step right back into the fray once the mission is concluded with our return to the church.

We'd intrigued to see how the difficulty ramps up, and how, given the sandbox nature of the city; while a side-mission that sees us boxed into an alley's dead-end and attacked by human assailants suggests there's much more to the game than is being explained, so we have hopes the storyline delivers too, even if it does go down the traditional routes. We're told there's and extensive network of sewers that can be used under the island - might there be a secret lab down there as well?

But in all, Dead Island offers something different in a market that really, DLC zombie appearances aside (hello Red Dead and Black Ops!), hasn't been bled to death just yet. It's definitely not a Left 4 Dead clone, and may in fact set down a template which future developers will follow.

When the FPS battlefield rages this winter, Dead Island will be picking up the dead and recruiting for its own distinct experience to wage war on the online charts. Big is indeed better, and Dead Island could be very big indeed.